#!/usr/bin/env node

const http = require('http'),
      qs   = require('querystring'),
      fs   = require('fs'),
      log  = console.log;

let items = ['eat','sleeping'],
    result = {
      status:200,
      reason:'ok'
    };
http.createServer((req,res) =>{
  logRequest(req);
  if(req.url.slice(0,5) !== '/todo'){
    let html = fs.readFileSync('./12-todo.html').toString('utf8');

    if(req.url === '/'){
      res.end(html);
    }else if(req.url == '/12-todo.js'){
      fs.createReadStream('./12-todo.js').pipe(res);
    }else{
      res.end('not api request and not page request!');
    }
    return;
  }
  switch(req.method){
    case 'GET':
      select(req,res);
      break;

    case 'POST':
      insert(req,res);
      break;

    case 'PUT':
      update(req,res);
      break;

    case 'DELETE':
      remove(req,res);
      break;

    default:
      res.end(`${req.method} method not support!`);
  }
}).listen(8080);

function logRequest(req){
  log(`${req.method} ${req.headers} HTTP/${req.httpVersion}`);
  log(req.headers);
  log();
}

function select(req,res){
  result.data = items;
  res.end(JSON.stringify(result));
}

function insert(req,res){
  let data = '';

  req.on('data', chunk => data += chunk);
  req.on('end', () => {
    let item = qs.parse(data).item;

    if(item !== '' && typeof item !== 'undefined'){
      items.push(item);
      res.end(JSON.stringify(result));
    }else{
      result.status = 401;
      result.reason = 'item is empty';
      res.end(JSON.stringify(result));
    }
    
  });
}
function update(req,res){
  //get id
  let id = req.url.split(':')[1];
  //validate id 校验id
  //data type
  //value min=0, max=items.length
  
  //get item
  let data = '';
  req.on('data', chunk => data += chunk);
  req.on('end',() => {
    //update items[id] = item;
    let item = qs.parse(data).item;
    if(item !== '' && typeof item !== 'undefined'){
      items[id] = item;
      res.end(JSON.stringify(result));
    }else{
      result.status = 401;
      result.reason = 'item is empty!';
      res.end(JSON.stringify(result));
    }
  });
  
}
function remove(req,res){
  //get id
  let id = req.url.split(':')[1];
  
  //id not exist   del all
  if(typeof id === 'undefined'){
    items = [];
    result.status = 200;
    result.reason = 'delete all success';
    res.end(JSON.stringify(result));
    return;
  }else{
    items.splice(id,1);
    result.status = 200;
    result.reason = 'del success';
    res.end(JSON.stringify(result));
  }
  //id exist
  //valide id
  //id is ok del items[id]
  
}
